They're just called "fluorescent" bulbs in States, too, but it has been
general knowledge for for as long as I can remember (& that's long!) that
the insides contain "poison." We are advised to handle and dispose of
broken bulbs with great care and especially not to get cut by the glass.
That there is mercury inside is I suppose not on the label, but widely
known here as well. (Not that "widely known" is proof, of course, but in
this case the facts seem to agree with the legend.)
Judy